1. Field of the Invention
The present invention generally relates to a novel silazane compound, a method for enhancing adhesive strength of a photoresist film, and a method of forming a photoresist pattern using the silazane compound. More particularly, the present invention generally relates to a (dichlorotetramethyl)disilazane compound, and a method of forming a photoresist pattern using the (dichlorotetramethyl)disilazane compound.
A claim of priority is made to Korean Patent Application No. 2004-3307 filed on Jan. 16, 2004, the content of which is incorporated herein by reference in its entirety.
2. Description of the Related Art
Semiconductor devices with a higher degree of integration and faster response speed are required as information processing systems have rapidly developed. Hence, the technology for manufacturing the semiconductor devices has been developed to improve the degree of integration, reliability, and response speed of the semiconductor devices. Accordingly, a micro-processing technology such as a precisely performed photolithography process is required to improve the degree of integration of the semiconductor device.
In a conventional photolithography process, an organic photoresist film having a pattern layer is formed on a substrate. After exposing the photoresist film to light, the photoresist film is developed to form a photoresist pattern by removing exposed portions of the photoresist film. Afterwards, any remaining photoresist residue is removed from the substrate.
However, since characteristics of the substrate are substantially different from those of the photoresist film, the photoresist film may not be uniformly coated on the substrate. Hence, the photoresist pattern may be lifted from the substrate during the removing process. When a semiconductor device is highly integrated, the above-described problem deteriorates the reliability of the semiconductor device. For example, when a photolithography process is performed to form a bit line having a line width of several tens of nanometers using an argon fluoride (ArF) laser, the photoresist pattern collapses due to the high aspect ratio.
The collapsing of the photoresist pattern can be prevented by enhancing the adhesive strength between a substrate and a photoresist film. A conventional method of increasing the adhesive strength between a resist film and a substrate is disclosed, for example, in Japanese Patent Laid Open Publication No. 1983-188132. In the method, after a substrate is treated with a compound or a solution containing the compound, a resist composition is coated on the substrate to form the resist film. The compound is represented by a chemical formula of R1SiX3-nR2n or [R1SiR22]2NH wherein n is 0, 1 or 2, X is a halogen or —OR′ group (R′ is an alkyl group having 1 to 3 carbon atoms), R1 is CH2—CH—, ZOH2— (Z is a halogen) or a group including OCH2CH—, and R2 is hydrogen or an alkyl group having 1 to 3 carbon atoms.
Korean Patent Laid Open Publication No. 2001-77196, for example, provides a method of enhancing adhesive strength between a substrate and a photoresist film using a compound in accordance with the chemical structure:

n is an integer of 2 to 8, and R is a hydrogen atom or an alkyl group having 3 to 6 carbon atoms. Here, the hydrogen atom of the alkyl group may be substituted for a halogen atom. However, the compound can only be used for a photoresist film that is exposed using a deep ultra violet (UV) light. Thus, if the compound is used for a photoresist film having strong hydrophobic characteristics that is exposed using an argon fluoride (ArF) laser, which has a relatively short wavelength, the increase of the adhesive strength between the substrate and the photoresist film is minimal. Accordingly, the compound cannot be used for forming a photoresist pattern with a high aspect ratio.